HC908 Software

Software for the HC908 hardware test platform

Download the Source and binary files for the two latest versions ...                                                          .
Version 3b --  Supports the DDS-30 card with standalone LCD user interface.  .
4a --  Supports both DDS-30 card and DDS-60 card via serial link to PC

"Exerciser" is a simple application that is controlled via the RS-232 serial port and is used to demonstrate use of typical I/O peripherals one might use with the processor. Exerciser provides a set of library routines and drivers for the various hardware components comprising the Digital Breadboard project: LCD, keypad, DDS, A/D Converter, shaft encoder and EEPROM. These library routines are individually selectable from a menu presented sent to the serial  port, allowing the user to invoke any of the functions for test purposes.  Further, the user may conveniently modify the Exerciser program to serve as the starting point for custom program development.

‘Exerciser’ is located at the “user application” address of 8000 and comes pre-loaded on all initially-supplied HC908 Daughtercards. (The other pre-loaded software program is the ‘HCmon’ debug monitor loaded from location E000 to FFFF.)

The Exerciser user application is controlled by an external terminal program connected to the daughtercard’s serial port and serves at least two main roles. First, it provides the user with a ready-made program that exercises (or demonstrates) some standard peripheral functions that can be used in a typical project employing the HC908 Daughtercard. Of course the various peripheral hardware components must be present and connected to the daughtercard for the program to work as described, and these peripherals include: an LCD display, a shaft encoder, a piezo-electric sounding device, a number of discrete LEDs and a serial port connector.

The second role performed by the Exerciser program is that of a daughtercard tester. Each HC908 Daughtercard made is placed into the a “test fixture” consisting of the hardware peripherals mentioned above. (Refer to the Test Fixture schematic). A special connector is wired to specific I/O pins on the J1 and J2 connectors of the daughtercard, and the HCmon and Exerciser programs are burned into flash memory on the 68HC908AB32 microcontroller. This initial “boot strap programming” of the debug monitor program (at least) is necessary to make the daughtercard intelligent enough to handle subsequent repeated loadings/burnings of custom programs into its user application memory space.  


Last Modified:  June 8, 2010